May 18 (Bloomberg) -- A tropical cyclone in the Bay of
Bengal heading toward India’s east coast may stall the progress
of the monsoon, which accounts for four-fifths of the nation’s
annual rainfall, a weather bureau official said today.

The monsoon system over the Bay of Bengal and the Andaman
and Nicobar islands may “disintegrate” after tropical cyclone
‘Laila’ makes landfall on May 20, D. Sivananda Pai, a director
at the India Meteorological Department, said in a phone
interview. It may take a week for the monsoon to regroup and
advance further, he said.

India’s 235 million farmers rely on the timing of the June-September monsoon to decide which crops to grow. Normal rainfall
may lift farm output and cool food price gains after the weakest
monsoon since 1972 last year cut rice, corn and oilseed output.

“There will be a temporary weakening of the monsoon as two
equally powerful weather systems can’t survive in the same
area,” Pai said.

The cyclone, packing sustained winds of 65 kilometers (40
miles) an hour, was about 650 kilometers east of Chennai at 5:30
a.m. local time, the U.S. Navy Joint Typhoon Warning Center said.
Waves were 3.7 meters (12 feet) high near the storm’s eye, where
winds were gusting to 83 kilometers per hour.

The system was moving west-northwest at 17 kilometers per
hour and its winds were forecast to reach hurricane strength
from tomorrow, with gusts as high as 185 kilometers an hour as
it approaches the coast.

Monsoon Progress

Cyclone Laila may bring heavy rainfall along the coast of
Tamil Nadu and Andhra Pradesh states today, the Meteorological
Department said in a statement. Fishermen in the area have been
advised not to go to sea, according to the statement.

The monsoon may still begin over the southern Indian state
of Kerala by May 30, the weather bureau’s Pai said.

Farmers in India, the world’s second-biggest producers of
rice and wheat, rely on the rainy season to water their crops as
about 60 percent of arable land isn’t irrigated. Winter-harvested crops, including rice, corn, lentils, cotton and
soybeans, are planted after the monsoon begins.

Rains this year may be 98 percent of the 50-year average,
the Meteorological Department said April 23. Showers may reach
the southern Kerala coast May 30, the weather bureau said May 14.

India is regularly buffeted by cyclones that form in the
Bay of Bengal between April and November, bringing destruction
and flooding to coastal communities. Tropical Cyclone Aila,
which disrupted the monsoon last May, left 169 people dead and
affected more than 7.7 million people in India and Bangladesh.